precast-tech

precast-tech

Explanation and treatment methods for cracks and diseases in bridge and tunnel concrete

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Vertical cracks appear in the middle of the beam span, penetrating along both sides of the beam.

Precast Round Ferrule

The reason is that when the concrete is subjected to a load, the steel bars in the lower tensile zone are jointly stressed with the concrete.

When the fiber strain at the edge of the tensile zone is greater than the ultimate tensile strain of the concrete under bending, concrete cracking occurs in the tensile zone.

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Is it good to pour concrete in cold winter weather? In depth analysis of the challenges and professional solutions of winter concrete

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With the promotion of year-round operations in the construction industry, winter construction has become increasingly common.

Edge Lift Anchor

However, whenever the temperature drops sharply, the core challenge faced by construction is whether pouring concrete in cold winter weather is feasible?.

Must see for engineers: the core cause of high early strength and slow later growth of concrete

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As a key indicator for engineering quality control and acceptance, concrete strength naturally attracts the attention of technical personnel and construction units in concrete enterprises.

In concrete production and engineering practice, there is often a phenomenon of “early stage deformity, later stage defects”, that is, the early strength of concrete is higher at 7 days, and the strength growth is slow after 28 days.

Excessive early strength growth not only inhibits later strength improvement, but also increases the difficulty of controlling concrete cracks due to high hydration rate and heat of hydration, thereby adversely affecting the durability of concrete.

Rebar Wheel Spacers

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How to find the cause of color difference in concrete?

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After decades of development, both the mix proportion and production process of concrete are relatively mature.

However, the uneven quality and frequent fluctuations of raw materials, as well as the frequent occurrence of concrete quality problems caused by untimely or inadequate adjustment of concrete mix proportion, are the current difficulties in concrete quality control.

For example, the phenomenon of pipe blockage caused by poor aggregate wrapping, segregation, bleeding, or significant loss of slump over time in concrete mixtures is rampant.

The problem of unqualified engineering quality caused by fluctuations in raw materials, such as insufficient strength of concrete test blocks to meet design requirements or large strength dispersion, is not uncommon.

With the increasing efforts in environmental protection, unstable raw material quality has become the norm.

Understanding the current status of concrete raw materials, adapting concrete production to fluctuations in raw material properties, and improving concrete quality are of great significance.

Swift Lift Foot Anchor

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The influence of coarse aggregate on the compressive strength of concrete

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In low strength grade concrete, the amount of cementitious material used is small, and the amount of slurry is also small.

Increasing the particle size of the aggregate appropriately and reducing the specific surface area can reduce the amount of slurry used, increase the compactness of the concrete, and improve its strength.

Swift Lift Foot Anchor

But it’s not that the larger the particle size, the higher the concrete strength.

In high-strength concrete, the larger the particle size of the aggregate, the higher the probability of defects.

In concrete mixtures, the larger the particle size of the aggregate, the faster it sinks, resulting in poor uniformity and low strength of the concrete.

The use of small-sized aggregates in high-strength concrete can reduce aggregate defects, increase the bonding area between aggregates and cement slurry, and improve concrete strength.

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